Advertisements
Advertisements
Question
How is root hair adapted for the absorption of water from the soil?
Advertisements
Solution
The main root with its many branches form a network in the soil. The root hairs get entangled in the soil particles and remain in close contact with the capillary water surrounding the soil particles. The epidermal cells of root hairs have vacuoles which contain cell sap. Generally, the cell sap is more concentrated than the soil solution. As a result the water enters inside the root hair cells by endosmosis. This water dilutes the epidermal cell sap solution. Then water enters into the cortical cells by osmosis and reaches the endodermal cells and then pericycle cells. From this layer water then enters in the xylem tissue. In this way, the water is absorbed and translocated up to xylem of the root by osmosis.
APPEARS IN
RELATED QUESTIONS
The phenomenon of loss of water through a cut stem or injured part of plant is called ___________.
Mention whether the following statement is true or false. Correct the false statement by altering the last word only.
The cell wall of the root cell is a differentially permeable membrane.
The alongside diagram A shows a root hair growing through the soil particles. Diagram B is the root hair of an aquatic plant.
(i) Name the parts 1,2,3.
(ii) Name two substances which enter the root hair. What are their uses?
(iii) By what process do these substances enter the root hair?
(iv) Account for the different shapes of root hairs in the two diagrams.
Given below is the diagram of a cell as seen under the microscope after having been placed in a solution:
(i) What is the technical term used for the state/condition of the cell given above?
(ii) Give the technical term for the solution in which the cell was placed.
(iii) Name the parts numbered 1 to 4.
(iv) Is the cell given above a plant cell or an animal cell ? Give two reasons in support of your answer as evident from the diagram.
(v) What would you do to bring this cell back to its original condition?
Give Technical Term for the following.
Tissue which transports manufactured food from leaves to other parts of the plant.
Column ‘II’ is a list of items related to ideas in Column ‘I’. Match the term in Column ‘II’ with a suitable idea given in Column ‘I’.
| Column I | Column II |
| (i) Diffusion | (a) The exit or flow of water from the cell to the outer environment. |
| (ii) Xylem | (b) The shrinkage of protoplasm when the cell is kept in a hypertonic solution. |
| (iii) Root pressure | (c) The tissue through which water and mineral salts move upward in a plant. |
| (iv) Isotonic solution | (d) Two solutions which have equal osmotic pressure. |
| (v) Exosmosis | (e) The process by which the molecules of perfume spread in the room when the bottle is open. |
| (vi) Osmosis | (f) The process by which roots absorb water from the soil. |
| (vii) Plasmolysis | (g) The pressure by which water rises up to some feet in a lofty tree. |
| (viii) Hypotonic solution | (h) The concentration of the solution when lower than that of the cell sap. |
Plasma Membrane is ______.
From which type of cells, root hair is originated
Root hair is a cytoplasmic extension of ______.
